tothe

Letters

Dear

coffee

and

serum

LDL-cholesterol

tation provided is that consumption of decaffeinated no coffee causes an increase in LDL cholesterol. worthwhile to suggest that consumption ofcaffeinated

Sir:

The role of coffee rotic coronary artery

consumption in the etiology of atheroscledisease has been the subject ofa long debate

easily

the

encompassing

troduction

past

of a variety

rations

now

in use.

30 y. This

of brewing

The

recent

debate

predates

methods

report

and

This area ofinquiry is notable for its inconsistency It seems clear that caffeine, despite its indictment

identify

decaffeinated

(5, 7, 8). How

these

other

Several

then

might

as being

the study

aspects

ofthe

need

with the continued

design

further

than

by Superko

and

coffee

et al differ

from

issue of compliance. drinking of subjects’

the control

group,

decaffeinated

coffee

the

with

being

continued

ofthe

toward

Superko

this end.

The

The study design usual caffeinated

with

abstinence

experimental

consumption

dictated coffee

ofcaffeinated

drinkers,

and

or no-coffee

creasing

interesting, in the same

with other direction.

usual consumption rate, Apparently, at least one

or did subject

their was

groups

may

be interpreted

also

coffee’s

The

report

effect

is mediated

by Superko

of this

brewing

However,

tically

different

terol.

Most

none from

studies

of these the baseline

of coffee

in lipid

concentrations

another

group’s

differences

topic.

method,

To

and

with

values.

The

concentration

consumption

the

to the

possibly

results

suggest

coffee

from

is left wondering groups the

no-coffee 604

around

decrease

baseline whether

an average in LDL

groups?

values the results

for the

with

in the

than

is the significant

the type

study

the

beans

steps

substance? explain

Any

Can the

the

recommendation

the grounds

of health and

phenols

differences?

What

of one

concerns,

explanation

ofthe

should

NY

Bassett

add

con-

a cholesterol-

in certain

types

of coffee

results

be if the

the

with caffeine

of coffee

await

observations

Research

Usually,

of coffee

would

sample form

the de-

factor for used in the

describing. that

the

bean,

the removal

can be hypothesized

com-

consumed,

of coffee

is worth

suggests

serum lipase ratio. decaf-

over

and one

another

on

the confirmation, by Superko et al. Thomas A Pearson

Institute

13326-1394

References

coffee

is the

The

one

between cause

caffeinated-coffee

trend?

raising

Cooperstown,

with

it. Thus,

variation What

What

process

The Mary Imogene One Atwell Road

choles-

caffeinated

represent

of no change.

cholesterol

Which

associated

stituents.

expansion,

or no coffee has as large a decrease from baseline values of LDL cholesterol associated with it, whereas decaffeinated coffee has

an increase

or both in lipo-

the changes

rather

that

of cups

between

of LDL

values

in de-

enzymes. emphasizes

number

one-

to be statis-

compare

baseline

by these

et al correctly

decaffeinated

LDL cholesterol

appear

only one decrease

is as-

decreased by 0. 1 1 mmol/L in the caffeinated-coffee and no-coffee groups, but increased by 0.12 mmol/L in the decaffeinated-coffee

group.

effect

coffee

their

that con-

hepatic triglyceride lipases is unique and

caffeination process should be added as a possible analysis. In this regard, the method ofdecaffeination

rate change up or down? unable to continue. The

differently.

coffee’s

increasing effect on

choles-

a less

com-

degree of crossover between groups would be essential interpretation of study results. Second, the magnitude and significance ofdifferences study

It seems provide

Thus,

to continue

in the

by a fall in LDL

drinkers.

or as or

6% difference,

protein lipase probably should be reflected in increased triglycerides. A significant increase in hepatic triglyceride probably should cause an increase in the HDL2-HDL3 Neither were observed. Thus, it seems speculative that

same coffee beans were used-one sample without caffeine?

able

coffee It seems coffee

cholesterol

drugs usually affecting A clinically significant

Were

subjects

The

would

lipoprotein lipase and is unclear. This opposite

the decaffeination

decaffeinated-coffee

half

explanations

sumed, but what was the compliance in the other two groups? Was the abstinent group able to abstain? Earlier studies of coffee consumption observed the need for subjects randomly assigned to abstinence to be allowed some form of hot beverage (9, 10).

the

cholesterol.

for by a rise in LDL

sided interpretation of findings. Finally, the significance of decaffeinated

plexity

to

in LDL

of alternate

feinated

first

or change

groups.

a fall

in the caffeinated-

sideration

lipase

regular

interpretation

clarification

characterized pliance

by the popular

elevation (2-5). One coffee, is, in fact, the studies have failed to

worse

causes

is half accounted

terol

namely desubstances cholesterol. of findings.

studies?

et al study deals that

coffee

then,

decaffeinated-coffee

et al (1) focuses

of coffee, it contains (LDL)

media, is not responsible for cholesterol cholesterol-raising component of boiled lipid-soluble fraction (6). Moreover, other

no coffee

in-

prepa-

coffee

by Superko

on one of these more recent preparations caffeinated coffee, and the concern that that might raise serum low-density-lipoprotein

the

concentrations

for and

interpre-

Am J C/in Nuir

l992;56:604-l0.

1. Superko

HR. Bortz W, Williams PT, et al. Caffeinated and decaffeinated coffee effects on plasma lipoprotein cholesterol, apolipoproteins, and lipase activity: a controlled, randomized trial. Am I CIin Nutr l99l;54:599-60S. 2. Thelle DS, Heyden 5, Fodor 1G. Coffee and cholesterol in epidemiological and experimental studies. Atherosclerosis 1987;67:97103. 3. Davis BR, Curb D, Borhani NO, et al. Coffee consumption and serum cholesterol in the Hypertension Detection and Follow-up Program.

Printed

Am

I Epidemiol

1988;128:124-36.

in USA. © 1992 American

Society

for Clinical

Nutrition

Downloaded from https://academic.oup.com/ajcn/article-abstract/56/3/604/4715434 by McMaster University Library user on 03 February 2019

Decaffeinated

Editor

LETTERS 4. Shirlow MI, Mathers CD. Caffeine consumption lesterol levels. Int I Epidemiol 1984; 13:422-7. S. van Dusseldorp M, Katan MB, Demacker PNM.

and

TO

serum

Effect

cho-

of decaf-

Reply Dear

I would

like

to respond

to the

comments

of Pearson

for the

authors. First, our has no effect

randomized trial on the lipoprotein

point

was

Second, is the

trial

involved

number

emphasized

Pearson

sign

of any

results

was

of randomization

by

classic

group

assignment.

of subjects

in their suspicion of assignment to this group. was developed over 2 y and underwent intense

in the decaffeinated

(NIH)

group group

Questionnaires

that

ofHealth

cal-

as to the

or decaffeinated-coffee

vealed

Institutes

The

power

correct design

the National

Our

were blinded

caffeinated-

de-

participants.

subjects placed in the no-coffee assignment and the decaffeinated

of their

60%

Trial

investigation.

many

and subjects into

those group

issues.

clinical with

determined

The investigators

suspicious

good

coffee study.

section.

trial-design

design

of participants

that caffeinated measured in our

discussion

several

a randomized

groups. Certainly, were aware oftheir

indicates variables

in the

addresses

foundation

culations.

was

Third,

the

was

issue

of compliance

determined

Coffee Dear

DS. Coffee

and

article

coffee

Study

by the

is an important difference

lipoprotein

one.

by

Superko

diet

records.

and ingestion There

groups. There Fourth, the

NIH-funded

between

groups.

clinical leading variables

returned

was

was

no

study This

at each

determined

Compli-

between

the

to test

is the purpose

ofhaving

calculations the main

were performed to design hypothesis. We believe that

et al (1)

on

coffee

and

regular

could

take

of coffee drinking led to a decline 2) Under Laboratoryprocedures C concentration was formula for calculating LDL-C

terol,

C is cholesterol, and

TG

In Results observed

coffee

After

as before.

total HDL

With

the position

that

in LDL-C. it is clearly

stated

Berkeley,

C - (HDL-C

+

they

the no-

the cessation that

LDL-

practice. The is as follows:

TG/5)

is high-density-lipoprotein

choles-

is triglyceride. it is stated

for changes

that

Superko

Center

Berkeley Laboratory of California CA

94720

Reference I . Superko HR, Bachorik cholesterol measurements.

“No

in concentration

3)

In Table are

PS, Wood PD. High-density JAMA l986;256:27 14-7.

significant of plasma

differences triglycerides,

1 (Baseline

definite

lipoprotein

with

the

in the

other

small, 4

237

but

)

intakes

are

two

of the

groups.

Their

Admittedly, ofthe

6)

and

two measurements completion of the

three

TGs

the

differences

Cups per day are described as follows: mL of fluid coffee” as opposed to the

Only upon

calculated groups)

decaffeinated-coffee

group are

higher,

values are Also, their

differences

that

are

is surprising.

“each cup equal to generally accepted

definition of a cup constituting 150 mL. 5) Statistical analyses were applied to group tween baseline and end-of-study measurements lowing each subject to be his own control.

were

the

are higher, their HDL-C B values are higher.

lower.

it is the consistency

or apo-Asubjects.” If ofthe equa-

could

characteristics

differences

their total C concentrations lower, and their apolipoprotein carbohydrate

calculated. This is the usual the LDL-C concentration =

in

lipoprotein

H Robert Research

as compared

one

groups

subtle

total cholesterol, HDL cholesterol, HDL2 cholesterol, I for the decaffeinated-coffee group vs the control there were no differences in any ofthe components

lipoprotein

showed

(LDL-C).

to drink

of change

that could answer with smaller pop-

ulations may lack the statistical power to reveal differences induced by components of coffee.

all,

drinkers

in low-density-lipoprotein-cholesterol at least

addressed

cholesterol

1, the caffeinated-coffee

continued

was

control

a trial studies

there

group

between

for significance

a decline

in Figure

and

in compliance

between groups. of the study that

was

Compliance

trials. Testing for a change from baseline can be misbecause it does not take into account the multitude of that can alter lipoprotein measurements (1). The power

Lawrence University

by

visit.

by questionnaire

difference

was no crossover statistical design

in this

were

We believe

in weight

no coffee

The trial review by

group

Section.

dispensed

with

why,

where

Br

coffee

tion for the calculation of LDL-C, how value have shown a significant increase?

merely

cholesterol.

SF, Arnesen E, et al. The Tromso Heart Study: and serum lipid concentrations in men with a randomized intervention study. Br Med I

cholesterol raises many questions requiring further explanation before the authors’ conclusions can be accepted with confidence. 1) From the data presented it is impossible to understand

coffee

and serum

10. Forde OH, Knutsen coffee consumption hypercholestcrolaemia: 198S:290:893-S.

Cholesterol

Sir:

The

9. Arnesen E, Forde OH, Thelle Med I 1984;288:1960.

re-

our investigation is the only US coffee investigation funded the federal government and not by commercial interests. ance

8. Fried RE, Pearson TA, Levine DM, et al. The effect offiltered coffee consumption on plasma lipids: results ofa randomized clinical trial. JAMA 1992;267:81 1-S.

to TA Pearson

Sir:

This

605

EDITOR

differences instead

of lipids were obtained: study. Thus, one does

not

beof alat entry know

Downloaded from https://academic.oup.com/ajcn/article-abstract/56/3/604/4715434 by McMaster University Library user on 03 February 2019

feinated coffee versus regular coffee on serum lipoproteins. Am I Epidemiol 1990; 132:33-40. 6. Zock PL, Katan MB, Merkus MP, et al. Effect ofa lipid-rich fraction from boiled coffee on serum cholesterol. Lancet 1990;335:l23S-7. 7. Bun- ML, Gallacher JEI, Butland BK, et al. Coffee, blood pressure and plasma lipids: a randomized controlled trial. Eur I Clin Nutr l989;43:477-83.

THE

Decaffeinated coffee and serum LDL-cholesterol concentrations.

tothe Letters Dear coffee and serum LDL-cholesterol tation provided is that consumption of decaffeinated no coffee causes an increase in LDL ch...
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